Cancer Risk in Xeroderma Pigmentosum Heterozygotes

This study will determine if family members of patients with xeroderma pigmentosum (XP) have various abnormalities, including: skin abnormalities; nervous system abnormalities, such as hearing problems; skin, eye, or internal cancers, or other changes. XP is a rare inherited disease that involves an inability to repair damage to cell DNA (genetic material). It can affect several organ systems, including the skin, eye, nervous system, and bones. Patients have a more than thousand-fold increase in frequency in all major skin cancers.

Parents of patients with XP are carriers of the abnormal XP gene. Other family members may also be carriers of the abnormal XP gene. Carriers do not develop the disease themselves; symptoms develop only in children who have inherited the faulty gene from both parents. This study will try to clarify the genetic basis for XP and to understand the increased frequency of cancer in the disease.

XP patients who have been evaluated at the NIH Clinical Center and their relatives are eligible for this study. Newly diagnosed XP patients are also eligible. Spouses of relatives will also be included as control subjects.

Patients and their family members will undergo some or all of the following procedures:

• Parental permission to review the child s relevant medical records and pathology material from treatments or surgery for cancer or other related illnesses
• Medical history and physical examination, with particular attention to the skin and possible eye, hearing or neurological examinations
• Photographs to document skin and other physical findings
• Nuclear medicine scans to evaluate the brain and nervous system
• X-rays of the skull or other parts of the body
• Nervous system testing with an electroencephalogram (EEG), electroretinogram (ERG), electromyogram (EMG) or nerve conduction velocity measurement
• Collection of blood and skin samples for gene studies
• Establishment of cell lines from collected blood or tissues to study DNA repair, skin cancer, cancers related to XP, immune defects, and related studies.
• Biopsy (surgical removal of a small piece of tissue) of suspicious skin lesions for examination under a microscope
• Collection of a cheek cell sample, obtained by twirling a soft brush against the inside of the cheek
• Collection of a hair sample for microscopic examination and composition analysis
• Surgery to treat skin cancers or other lesions